Bump css-loader from 3.3.0 to 3.4.0 (#60)

Bumps [css-loader](https://github.com/webpack-contrib/css-loader) from 3.3.0 to 3.4.0.
- [Release notes](https://github.com/webpack-contrib/css-loader/releases)
- [Changelog](https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack-contrib/css-loader/compare/v3.3.0...v3.4.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -46,7 +46,7 @@
     "clean-webpack-plugin": "^3.0.0",
     "copy-webpack-plugin": "^5.0.5",
     "copyfiles": "^2.1.0",
-    "css-loader": "^3.3.0",
+    "css-loader": "^3.4.0",
     "eslint": "^6.4.0",
     "eslint-config-prettier": "^6.3.0",
     "eslint-plugin-jest": "^22.2.2",